The aim of this study was to determine the prevalence and the type-distribution of high-risk HPV (hrHPV) genotypes according to age and severity of cervical lesion in female population of Zagreb region.
The study included all women, who were during the eight-month period (December 2013-July 2014), on their gynaecologist's request, tested on hrHPV infection with the real-time PCR test (Cobas HPV Test). The examinees were divided according to age in two main groups (<30 years and ≥30 years) and according to the severity of cervical lesion, based on Pap test result, in two groups (ASCUS/CIN1 as LSIL and CIN2/CIN3 as HSIL). Differences between observed groups were compared by using Fisher’s exact test with p value <0.01 considered statistically significant.
Out of the 3542 women tested, hrHPV infection was detected in 39.7% (52.8% in women younger than 30 years and 32.9% in the age group ≥30 years; p<0.01). All detected types (HPV16, HPV 18 and the group of other twelve hrHPV types - 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68) were more common in younger women, especially in teenagers, were the prevalence of hrHPV infection was as high as 68.8%. In 749 women with LSIL the hrHPV infection was detected in 41.9%, while out of 363 women with HSIL 61.2% were hrHPV positive (p<0.01). The portion of HPV 16 significantly increased with severity of cervical lesion (28.3% in LSIL, 40.1% in HSIL; p<0.01), while the portion of the group of other hrHPV types was more common in LSIL (82.8%) than in HSIL (71.2%) (p<0.01). In women ≥30 years old infection with HPV 16 was significantly more common as single-type (69.6%) compared to women younger than 30 years were single-type infection with HPV 16 was detected in 37.5% (p<0.01). The same was observed for HPV 18 (57.4% in older and 31.3% in women younger than 30 years; p<0.01).
This study confirms existing data about higher HPV prevalence rates as well as predominance of multiple HPV infections in younger age groups. Furthermore, the prevalence of HPV 16, as expected, was higher in more severe cervical lesions.